Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed. An example system includes: interface circuitry; programmable circuitry; and instructions to program the programmable circuitry to: obtain audio of a media presentation; obtain ambient noise in an area associated with the media presentation; determine an intensity of a difference between the audio and the ambient noise; and determine an engagement level of an audience of the media presentation based on a duration the intensity satisfies a threshold value.

Abstract: Methods and apparatus are disclosed to determine a power state of a device. An example method includes determining respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, determining a first threshold and a second threshold based on at least one of the counts, the first threshold determined using most frequently logged measurement values, the most frequently logged measurement values based on counts performed after expiration of the calibration period, comparing a measurement to the first threshold and to the second threshold, and outputting a positive indication when the measurement is within an acceptable difference range, the acceptable difference range based on the amount of power drawn by the device.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to determine performance of audience measurement meters. An example apparatus disclosed herein is to cause an audio output device of a meter to emit an audio signal into an environment, the audio signal based on a test pattern including a first plurality of watermarks and cause an audio input device of the meter to collect data from the environment during emission of the audio signal. Additionally, the example apparatus is to determine whether a second plurality of watermarks decoded from the data match the first plurality of watermarks and based on a difference between the first plurality of watermarks and the second plurality of watermarks indicative of a fault, cause an alert to be transmitted to a device associated with an audience measurement company that issued the meter.

Abstract: Example meters disclosed herein include a user interface to accept user input in response to activation of a prompting indicator. Disclosed example meters also include a controller to control a light projector to project light onto a first projection area of a surface, the light projector activated in association with the activation of the prompting indicator. In some examples, the controller is also to control the light projector to project light onto a second projection area of the surface in response to expiration of a time period without receipt of any user input responsive the activation of the prompting indicator.

Abstract: Example invertible meter apparatus and related methods are disclosed. An example meter to monitor a media device includes a housing defining a cavity and a display area. The display area is separated from the cavity via a wall defining the display area. metering circuitry is positioned in the cavity of the housing. A stencil is to couple to the display area. The display area to be accessible from an exterior of the housing and is structured to removably receive the stencil without accessing the cavity or exposing the metering circuitry.

Abstract: Example meters disclosed herein include a user interface to accept user input in response to activation of a prompting indicator. Disclosed example meters also include a controller to activate a light projector to project light onto a first projection area of a surface, the light projector activated in association with the activation of the prompting indicator. In some examples, the controller is also to control the light projector to project light onto a second projection area of the surface in response to expiration of a time period without receipt of any user input responsive the activation of the prompting indicator.

Abstract: Methods and apparatus to analyze microphone placement for watermarks and signatures are disclosed. An example instructions cause one or more processors to at least determine a variance of a magnitude spectrum of a frequency band corresponding to a frequency spectrum of a first audio signal sensed with an audio sensor. The example instructions further cause the one or more processors to determine, based on the variance, a recovery rate associated with at least one of watermark detection or signature generation to be performed on a second audio signal to be sensed with the audio sensor.

Abstract: Methods and apparatus are disclosed to determine a power state of a device. An example method includes determining respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, determining a first threshold and a second threshold based on at least one of the counts, the first threshold determined using most frequently logged measurement values, the most frequently logged measurement values based on counts performed after expiration of the calibration period, comparing a measurement to the first threshold and to the second threshold, and outputting a positive indication when the measurement is within an acceptable difference range, the acceptable difference range based on the amount of power drawn by the device.

Abstract: Example invertible meter apparatus and related methods are disclosed. An example meter to monitor a media device includes a housing having a display and a plurality of walls. Respective ones of the walls are between respective ones of openings such that the openings are isolated from adjacent ones of the openings. A removable stencil includes a plurality of visual indicators, where the visual indicators to align with respective ones of the openings.

Abstract: Methods and apparatus are disclosed to determine a power state of a device. An example apparatus includes a chart generator to determine respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, a calculator to determine a first threshold and a second threshold based on at least one of the counts, the first threshold determined using most frequently logged measurement values, the most frequently logged measurement values based on counts performed after expiration of the calibration period, and a comparator to compare a measurement to the first threshold and to the second threshold.

Abstract: Example metering apparatus and related methods are disclosed. An example apparatus disclosed herein includes a stencil and a housing having a display area. The display area has a recessed cavity defining a front surface of the display area. A front surface of the stencil is to be flush mounted relative to the front surface of the display area defined by the recessed cavity when the stencil is positioned in the display area of the housing. A cover is removably coupled to the housing to enable access to the display area.

Abstract: Example metering apparatus and related methods are disclosed. An example apparatus disclosed herein includes a stencil and a housing having a display area. The display area has a first recessed cavity and a second recessed cavity adjacent the first recessed cavity. The first recessed cavity is offset relative to the second recessed cavity such that the second recessed cavity defines a front surface of the display area and a peripheral lip of a front side of the housing. A cover is removably coupled to the housing to enable access to the display area. The second recessed cavity of the housing is to receive the cover. The cover is received by the second recessed cavity such that an outer surface of the cover is substantially flush mounted relative to a peripheral lip of the housing, and wherein a perimeter of the cover is substantially similar to a perimeter of the peripheral lip.

Abstract: Methods and apparatus to analyze microphone placement for watermarks and signatures are disclosed. An example instructions cause one or more processors to at least determine a variance of a magnitude spectrum of a frequency band corresponding to a frequency spectrum of a first audio signal sensed with an audio sensor. The example instructions further cause the one or more processors to determine, based on the variance, a recovery rate associated with at least one of watermark detection or signature generation to be performed on a second audio signal to be sensed with the audio sensor.

Abstract: Example meters disclosed herein include a user interface to accept user input in response to activation of a prompting indicator. Disclosed example meters also include a controller to activate a light projector to project light onto a first projection area of a surface, the light projector activated in association with the activation of the prompting indicator. In some examples, the controller is also to control the light projector to project light onto a second projection area of the surface in response to expiration of a time period without receipt of any user input responsive the activation of the prompting indicator.

Abstract: Methods and apparatus to analyze microphone placement for watermarks and signatures are disclosed. An example apparatus includes a microphone. The example apparatus further includes a meter to convert a noise burst detected by the microphone to a digital signal. The example apparatus further includes a signal transformer to determine a frequency spectrum of the digital signal. The example apparatus further includes a processor to determine a variance of a magnitude spectrum of a frequency band corresponding to the frequency spectrum and determine, based on the variance, a recovery rate associated with at least one of watermark detection or signature generation to be performed on an audio signal detected by the microphone.

Abstract: Methods and apparatus are disclosed to determine a power state of a device. An example apparatus includes a chart generator to determine respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, a calculator to determine a first threshold and a second threshold based on at least one of the counts, the first threshold determined using most frequently logged measurement values, the most frequently logged measurement values based on counts performed after expiration of the calibration period, and a comparator to compare a measurement to the first threshold and to the second threshold.

Abstract: Example meters disclosed herein include a prompting indicator to emit a prompt for user input. Disclosed example meters also include a controller to determine whether the meter is to transition to a first prompting mode, or whether the meter is to transition to a second prompting mode different from the first prompting mode, the meter to be able to operate in at least a quiet mode, the first prompting mode or the second prompting mode. The controller is also to activate the prompting indicator and a light projector when the meter is to transition to the second prompting mode, the light projector to project light. The controller is further to activate the prompting indicator, but not activate the light projector, when the meter is to transition to the first prompting mode.

Abstract: Methods and apparatus are disclosed to determine a power state of a device. An example apparatus includes a chart generator to determine respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, the counts indicating respective numbers of times the respective measurements were detected. The example apparatus also includes a calculator to identify a first threshold based on at least one of the counts, and determine a second threshold. The example apparatus also includes a comparator to compare a measurement to the first threshold and to the second threshold, and a state detector to store an indication that the device is in an indeterminate state if the measurement is greater than the first threshold and less than the second threshold.